DE102004014576A1 - Method and chassis arrangement for driving stability control of a motor vehicle - Google Patents

Abstract

The invention relates to a method for driving stability control of a vehicle in which, depending on a driving condition, a rear camber angle of the wheels of the rear axle is actively adjusted, a front anti-roll moment is exerted on the front axle and a rear anti-roll moment is applied to the rear axle, one of the ratios of the rear Anti-roll torque to the front Antiwankmoment reflecting rolling moment distribution is adjusted in dependence on the rear camber angle of the wheels of the rear axle. Furthermore, the invention relates to a chassis arrangement for carrying out such a method.

Description

The The invention relates to a method and a chassis arrangement for Dynamic Stability Control a motor vehicle.

to Dynamic Stability Control a motor vehicle are different intervention options and Known method. This is how active stabilizers compensate the roll tendency due to the occurring during cornering Transverse acceleration used. As a rule, both vehicle axles are for this purpose equipped with active stabilizers and those of the active ones Stabilizers exercised Abstützmomente or anti-momentum constant or sometimes variable on the distributed between two vehicle axles.

Farther are methods and devices for changing the camber angle in wheel suspensions known from motor vehicles. For axis concepts with a passive, automatic kinematic camber angle adjustment is the camber through the rolling movements and acting lateral forces automatically or passively adjusted. For axle concepts with active camber angle adjustment The camber angle is also increased by one or more actuators changed without the action of rolling or lateral forces. Such Radsturzwinkelverstellvorrichtungen are usually arranged at the rear because their implementation on the front axle due to the reduced space, the large steering angle and the drive shafts is difficult with driven axles.

By a camber adjustment on the rear axle are the transferable Lateral executives increased, so that opposite conventional driving testify with identical driving maneuver the required axle slip angle is reduced.

By the reduction of the slip angle at the rear axle at unchanged Slip angle changed at the front axle However, the self-steering behavior of the vehicle to an understeer tendency out. This is due to the simultaneous reduction of the yaw angle caused due to the reduced slip angle on the provided with a fall correction device rear axle. To the desired Driving course continues to follow without deviation, the slip angle at the front axle must through stronger Turning in to be magnified, thus the desired Yaw rate is reached or maintained. This is favored Effect due to the uneven distribution of Roll stiffness on the vehicle axles, usually at the front axle a higher one Roll stiffness is present as at the rear axle and therefore also at the front axle higher Side managers required become. Thus, a fall correction on the rear axle also increases the side guide on the rear axle, although the larger support part on the front axle is provided.

Of the Use of active stabilizers is provided in addition to passive Camber adjustments problematic because passive camber adjustments to change the fall require the rolling motion of the vehicle body. Become These rolling movements by active stabilizers or other roll stabilization systems compensated, an effective camber adjustment is no longer possible because no significant changes in angle anymore occur.

In front In this background, the invention is based on the object Method and a chassis arrangement for driving stability control a motor vehicle to create both a high roll stiffness as well as high lateral leadership enable more neutral driving behavior.

The solution This object is apparent from the features of the independent claims 1 and 6, while advantageous embodiments and developments of the invention the dependent claims are removable.

Of the Invention is based on the finding that the understeering acting adjustment of the camber angle at which the wheels are continue up to vehicle interior and thereby turn into the curve stem, advantageously combined with active stabilizers can be. According to the invention thus active at least on the rear axle Radsturzverstelleinrichtungen combined with active stabilizers.

By active stabilizers the distribution of the rolling moment and thus the required cornering shift between the axles, with a shift of the roll support on the rear axle the untersteuernd acting adaptation of the camber angle can compensate completely or partially. By relocating the anti-roll control on the rear axle is therefore due to the adaptation of the camber there opened additional Cornering potential actually retrieved. Thus, you can higher Side managers reached and also be exploited without the self-steering behavior of the vehicle to influence negatively.

Accordingly, the invention describes a method for driving stability control of a Fahrzeu ges, in which, depending on a driving condition, a rear camber angle of the wheels of the rear axle is actively set as well as on the front axle a front Antiwankmoment and on the rear axle a rear anti-roll torque are exercised. In addition, a rolling moment distribution representing the ratio of the rear anti-roll moment to the front anti-roll moment is set as a function of the rear camber angle of the wheels of the rear axle.

In Advantageous embodiment of this method can also be provided be that relationship the rear anti-roll moment is increased to the front anti-roll moment, when the rear camber angle of the wheels of the rear axle decreases becomes.

moreover can be provided that only the rear camber angle of the wheels of the Rear axle is actively set and a front camber angle of Wheels of the Front axle is passive.

According to one Variant of the invention will be first a regulation of driving stability performed after the rear camber angle and then the Rolling torque distribution adapted to the set rear camber angle.

A independent of it Variant provides that for a determined driving condition of the rear camber angle and the rolling moment distribution adjusted according to a characteristic field become. This is the chronological order of the setting of Rolling torque distribution and camber angle depending on the determined driving condition variable.

Finally, can be provided that only the rear camber angle is set active is, and that the front camber angle passive, that is automatically sets.

The Inventive chassis arrangement includes at least actuators for adjusting a rear camber angle the wheels the rear axle of the vehicle, a front active stabilizer for setting a front anti-roll moment on the front axle and a rear active stabilizer for adjusting a rear Antiwankmomentes on the rear axle, with a control device to adjust the ratio the rear Antiwankmomentes to the front Antiwankmoment reflecting Rolling torque distribution depending on from the camber angle of the wheels the rear axle is provided. It can be on every rear wheel Actuator or more actuators may be provided.

In preferred embodiment of this suspension arrangement is provided that the control device is designed such that with this The relationship the rear anti-roll moment is increased to the front anti-roll moment, when the rear camber angle of the wheels of the rear axle decreases becomes.

Finally, can be provided that on the wheel suspensions of the wheels Front axle only passive Radsturzverstellvorrichtungen provided are.

The Vehicle dynamics gained according to the invention Potential can be both for more comfortable tuning within a also reachable with a passive vehicle border area, as well to an increase in the limit of a passive vehicle appropriate suspension design can be used. This variation to a more comfortable and / or a sportier driving behavior can with only minor changes be achieved at the base landing gear, so that according to the invention with low hardware variations a big Bandwidth can be set to vehicle characters.

to Clarification of the invention, the description is a drawing attached. The figure shows a diagram of a steering wheel angle to be set in FIG dependence from the occurring lateral acceleration in various driving stability regulations or Suspension arrangements.

• a einer passiven Fahrwerksanordnung ohne aktive Komponenten zur Sturzverstellung oder Wankmomentabstützung,
• b konstantem Sturz = 0° ohne aktive Stabilisatoren,
• c negativem Sturz ohne aktive Stabilisatoren,
• d positivem Sturz ohne aktive Stabilisatoren und
• e negativem Sturz und aktiven Stabilisatoren.

In the figure, the adjusted by the driver steering wheel angle δ in degrees as a function of the vehicle occurring lateral acceleration ay in m / s ² reproduced for a chassis with

• a passive chassis arrangement without active components for camber adjustment or roll moment support,
• b constant fall = 0 ° without active stabilizers,
• c negative fall without active stabilizers,
• d positive fall without active stabilizers and
• e negative camber and active stabilizers.

This diagram shows the influence of the camber adjustment on the self-steering behavior. First, the influence of a camber adjustment on the self-steering behavior with and without adjusted roll stiffness distribution is shown by the stabilizers. Compared to the curve a of a passive vehicle without active suspension components lead negatively growing camber angle according to curve c in vehicles with active camber adjustment to a significant increase in Untersteuertendenz the vehicle, which has an increased steering demand and reduced steering compliance result. Because of the occurring Wank angle on the passive vehicle sets a positive camber angle, already shown in curve b, held constant at 0 ° camber angle leads to vehicles with camber correction to slightly amplified understeer. Conversely, according to the curve d, it is possible to tune the self-steering behavior of neutral by positive camber angle, whereby, however, the limit range of the achievable cornering force is reduced.

According to the curve e is due to a setting of a negative fall and under Using stabilizers about a 5% higher Grenzquerbeschleunigung reached, which is indicated by the arrow at the upper end points of the curves indicated. Here are the invention further increases to that effect, that also the understeering behavior in many areas by the active stabilizers is improved.

a

curve a passive suspension system without active

components for camber adjustment or roll moment support

b

curve a chassis arrangement with constant camber without active

stabilizers

c

curve a suspension system with negative camber without active

stabilizers

d

curve a suspension system with positive camber without active

stabilizers

e

curve a suspension arrangement with negative camber and active

stabilizers

ay

lateral acceleration of the vehicle

δ

steering wheel angle of the vehicle

Claims (8)

Method for driving stability control of a vehicle, depending on from a driving condition a rear camber angle of the wheels of the Rear axle is actively set, at the front axle a front Anti-roll torque and at the rear axle a rear anti-roll torque exercised become, where one is the ratio the rear Antiwankmomentes to the front Antiwankmoment reflecting Rolling torque distribution as a function of set the rear camber angle of the wheels of the rear axle becomes. Method according to claim 1, characterized in that that the ratio the rear anti-roll moment is increased to the front anti-roll moment, when the rear camber angle of the wheels of the rear axle decreases becomes. Method according to claim 1 or 2, characterized that only the rear camber angle of the wheels of the rear axle is actively adjusted and a front camber angle of the wheels of the front axle becomes passive established. Method according to one of the preceding claims, characterized marked that first a regulation of driving stability after the rear camber angle takes place and the rolling moment distribution the adjusted rear camber angle is adjusted. Method according to one of claims 1 to 3, characterized that for a determined driving condition of the rear camber angle and the rolling moment distribution adjusted according to a characteristic field become. Suspension arrangement for driving stability control a vehicle, wherein the landing gear assembly comprises at least: actuators for adjusting a rear camber angle of the wheels of Rear axle of the vehicle, a front active stabilizer for setting a front anti-roll moment on the front axle and a rear active stabilizer for setting a Rear anti-roll torque on the rear axle, wherein a control device to adjust the ratio the rear Antiwankmomentes to the front Antiwankmoment reflecting rolling moment distribution dependent on from the camber angle of the wheels the rear axle is provided. Suspension arrangement according to claim 6, characterized in that that the control means the ratio of the rear Antiwankmomentes increased to the front anti-roll moment when the rear camber angle the wheels the rear axle is reduced. Chassis assembly according to claim 6 or 7, characterized characterized in that to wheel suspensions of Wheels of the Front axle only passive camber adjustments are provided.